Why does no one seem to know about the Deuce? It may be Vegas' best kept secret. For a mere $7 or $8, you can get an all-day pass, and ride the Strip in comfort. You can even catch a ride to Fremont (which is, as we understand it, a $25 taxi ride) and the Stratosphere.
Perks:
The Deuce is actually cute and comfortable. The drivers are, for the most part, tolerant and good-humored. Ditto, the passengers. Service is frequent.
Downsides:
The Deuce has very few stops--you very much need to plan where you're going to get on and off. You need exact change. The busstops don't have roofs, so prepare to fry while waiting. And the Deuce is painfully slow at night, but that is the fault of traffic and slooooow pedestrians, not the bus.